• Journal of Korean Neurosurgical Society
• /
• v.62 no.2
• /
• pp.153-165
• /
• 2019

Objective : Spinal cord injury (SCI) is a very serious health problem, usually caused by a trauma and accompanied by elevated levels of inflammation indicators. Stem cell-based therapy is promising some valuable strategies for its functional recovery. Nestin-positive progenitor and/or stem cells (SC) isolated from pancreatic islets (PI) show mesenchymal stem cell (MSC) characteristics. For this reason, we aimed to analyze the effects of rat pancreatic islet derived stem cell (rPI-SC) delivery on functional recovery, as well as the levels of inflammation factors following SCI. Methods : rPI-SCs were isolated, cultured and their MSC characteristics were determined through flow cytometry and immunofluorescence analysis. The experimental rat population was divided into three groups : 1) laminectomy & trauma, 2) laminectomy & trauma & phosphate-buffered saline (PBS), and 3) laminectomy+trauma+SCs. Green fluorescent protein (GFP) labelled rPI-SCs were transplanted into the injured rat spinal cord. Their motilities were evaluated with Basso, Beattie and Bresnahan (BBB) Score. After 4-weeks, spinal cord sections were analyzed for GFP labeled SCs and stained for vimentin, $S100{\beta}$, brain derived neurotrophic factor (BDNF), 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase), vascular endothelial growth factor (VEGF) and proinflammatory (interleukin [IL]-6, transforming growth factor $[TGF]-{\beta}$, macrophage inflammatory protein [MIP]-2, myeloperoxidase [MPO]) and anti-inflammatory (IL-1 receptor antagonis) factors. Results : rPI-SCs were revealed to display MSC characteristics and express neural and glial cell markers including BDNF, glial fibrillary acidic protein (GFAP), fibronectin, microtubule associated protein-2a,b (MAP2a,b), ${\beta}3$-tubulin and nestin as well as anti-inflammatory prostaglandin E2 receptor, EP3. The BBB scores showed significant motor recovery in group 3. GFP-labelled cells were localized on the injury site. In addition, decreased proinflammatory factor levels and increased intensity of anti-inflammatory factors were determined. Conclusion : Transplantation of PI-SCs might be an effective strategy to improve functional recovery following spinal cord trauma.

• Journal of Industrial Technology
• /
• v.17
• /
• pp.213-218
• /
• 1997

This study is concerned with characteristics of bending collapse of aluminum members with multi-cell section. Aluminum is light so it is compatible of being used for vehicle structures members. Bending collpase behaviors of aluminum members with multi-cell section are very complex and tension failure mode are occured in experiment. In this paper, the aluminum members are modeled to be able to represent the tension failure mode and, characteristics of bending collapse of aluminum members with multi-cell section by experimental method are compared with the results of PAM-CRASH.

• Journal of electromagnetic engineering and science
• /
• v.5 no.2
• /
• pp.92-96
• /
• 2005

This paper presents a novel microwave oscillator incorporating a simple microstrip ring type resonant cell as its terminating resonance component. Reduced chip size, higher dc-ac power efficiency, superior harmonic characteristics can be achieved from the introduction of a compact microstrip ring resonator cell. The oscillator provides a second harmonic suppression of 26.51 dB and the output power of 2.046 dBm at 2.11 GHz.

• KSBB Journal
• /
• v.9 no.4
• /
• pp.412-417
• /
• 1994

The biodegradable characteristics of starch-filled polyethylene film by fungi were investigated. Aspergillus niger showed the highest cell growth among five species of fungi used in the experiment. Higher starch content gave the higher growth rate of A. niger; however, the kind of film or cutting direction did not give any effects on the cell growth. The use of vinyl trimethoxysilane for the stronger binding of starch and polyethylene did not inhibit the cell growth. When the starch content was higher than 10%, the elongation of the film decreased significantly after the growth of microorganism in the case of transverse direction samples.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2003.03a
• /
• pp.875-883
• /
• 2003

Slurry clay has much higher water content than liquid limit of clay and even if small loads apply, it suffers a great settlement. Accordingly it is very difficult to perform a general consolidation test about slurry clay because of high water content. In this study consolidation tests have been performed successfully using Rowe Cell Tester about 1 remolding clay and 3 slurry clays with a water content of 100%, 133% and 150%. From the test results compression index characteristics, secondary compression index characteristics and consolidation coefficient characteristics have been investigated about slurry clay and remolding clay. Also two kinds of theory, by Terzaghi theory and by Mikasa theory, has been used to calculate consolidation coefficients. Compared to the calculation results, they had a similar value of consolidation coefficient. However if Mikasa theory is applied in the field design, the period which reach to the required consolidation degree will be much reduced compared to the period by Terzaghi theory because the time coefficient T$\_$v/ by Mikasa theory is far smaller than T$\_$v/ by Terzaghi theory.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.29-32
• /
• 2008

Testing was conducted to determine the performance of a residential fuel cell system when subjected to DSS and WSS operation, especially for start-up and shut-down characteristics. In terms of start-up time, it took about 70min to start output power generation and stably to reach 1kW at cold start. Measurement of the characteristics of heat and power generation were carried out at start-up and shut-down time. Fuel gas is used for heating both reformer and stack from start-up to the beginning of power generation. In terms of start-up and shut-down characteristics, it was important to control the reformer temperature precisely. The average output water temperature during the rated output operation(960W) was $63.2^{\circ}C$ constantly. The results of the investigation are being used to develop a new test protocols for residential fuel cell system.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.167-170
• /
• 2006

In this paper, we study how the viewing angle characteristics of a bend cell can be compensated by uniaxial films such as positive a-plate, negative c-plate and circular polarizer. Especially, it is confirmed how the circular polarizer composed of a quarter-wave plate and a linear polarizer enhances the viewing angle characteristics by the $Poincar\acute{e}$ sphere representation. Also, additional compensation film is designed to improve the viewing angle characteristics of the cell by the $Poincar\acute{e}$ sphere representation.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.21 no.6
• /
• pp.481-485
• /
• 2016

When analyzing economic feasibility for installing a PV generation plant at a certain location, the prediction of possible annual power production at the site using the target PV panels should be conducted on the basis of the local weather data provided by a local weather forecasting office. In addition, the prediction of PV generating power under certain weather conditions is useful for fault diagnosis and performance evaluation of PV generation plants during actual operation. This study analyzes PV cell characteristics according to a variety of weather conditions, including ambient temperature and irradiance level. From the analysis and simulation results, this work establishes a proper model that can predict the output characteristics of PV cells under changes in weather conditions.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.10
• /
• pp.2687-2702
• /
• 1996

It is desirable that the implementation of next generation information infrastructure is the Integrated Network combining the satellite and the terrestrial network. The application of the ATM network being the dominant infrastrure of terrestrial network to the satellite network is being studied variously. Considering these concepts, this paper analyzes due to ATM transport via satellite, evaluates the degradation of QoS and proposes reliable method of ATM cell transport via satellite. Because ATM is investigated with the optical fiber which is almost error free characteristics, the practical application of ATM transport via satellite essentially need the channel coding(FEC:Forward Error Correction) to enhance BER performance. But using the FEC coding, satellite link has burst error characteristics which evoke severe performance degradation fo ATM QoS. Therefore in satellite link, we analyze burst error characteristics using experimental results of computer simulation. Then to compensate these characteristics, based on this analysis and HEC dual mode algorithm we propose various interleaver structures(Block interleaver, Intra interlever, and Inter-Intra interleaver) to improve cell transmission QoS. We execute performance evaluations of iterleaver structures by computer simulation.

• Proceedings of the KIPE Conference
• /
• 2007.07a
• /
• pp.438-440
• /
• 2007

This paper shows a new kind of push-pull switching converter for fuel-cell system and analyses the connected characteristics of it. In these characteristics, we are concerned about the high harmonic rate of output current, we also have designed the filter system for the inverter. Besides, the characteristics should be certified better if the ripple of the fuel-cell output current has been eliminated.